In the case of recording, onto a recording medium, various data continuous in point of time and/or capacity, e.g., picture data, speech data or musical sound data, etc., i.e., data to be continuously outputted at the time of reproduction (hereinafter referred to as picture musical sound data), such an approach is ordinarily employed to write those data into continuous areas on the recording medium. Particularly, with respect to the tape-shaped recording medium, since it is very difficult to momentarily provide access to discontinuous areas, in the case of recording the picture musical sound data onto such tape-shaped recording medium, such an approach is typically employed to write those data into continuous areas.
In addition, also in the case of recording those picture musical sound data onto a write once type disc shaped recording medium (only once writable disc), such an approach is typically employed to write those data into continuous areas in a manner similar to the tape-shaped recording medium.
However, e.g., in rewritable disc-shaped recording medium (rewritable disc), works for once writing data thereafter to delete (erase) such data are repeated. For this reason, in the case of recording those picture musical sound data onto the rewritable disc, when an approach is adopted to write those data into continuous areas in a manner similar to the case of the tape-shaped recording medium, there are instances where vast unusable space (blank) areas may resultantly take place.
Explanation will be given with reference to FIG. 1 in connection with the mechanism in which recording and deletion (erasing) operations of various picture musical sound data continuous in point of tie and/or capacity are repeated, whereby unusable space areas take place on the rewritable disc. Dotted lines in the figure indicate recordable space areas existing on the rewritable disc and double (solid) lines in the figure indicate already recorded areas existing on the rewritable disc.
Initially, in the state of (1), the rewritable disc is assumed to be in initial (initialized) state, i.e., recording areas are assumed to be all recordable space areas. Namely, the rewritable disc is placed in the state of blank disc. Usable space (blank) area of the rewritable disc at this time point (i.e., total capacity of the disc) is assumed to be 100.
Subsequently, in the state of (2), e.g., data A of capacity 25 is recorded with respect to the rewritable disc placed in the initial state of(1). Subsequently, in the state of (3), e.g., data B of capacity 50 is further supplementarily recorded with respect to the rewritable disc placed in the state where the data A has been already recorded. Subsequently, in the state of (4), the data A already recorded in the state of (2) is deleted (erased) from the rewritable disc placed in the state where the data A and the data B have been recorded. At the time point when the data A has been deleted (erased) in the state of (4), usable (available) area on the rewritable disc is separated (divided) and two space (blank) areas respectively having capacity 25 take place (i.e., total space capacity becomes equal to 50).
Subsequently, in the state of (5), let consider the case where data C of capacity 50 is recorded with respect to the rewritable disc placed in the state where the data A has been deleted (erased). In this case, there exists space area of rewritable disc corresponding to capacity 50. However, the space area corresponding to capacity 50 is not continuous space areas, but is separated (divided). For this reason, the data C of capacity 50 cannot be written into the continuous areas. Namely, this means that unusable space areas of total capacity 50 have taken place on the rewritable disc.
Moreover, as a method of using such a rewritable disc, there are instances where plural picture musical sound data reproduced at the same time are recorded at different times. For example, there are instances where picture data and speech data are recorded at times different from each other and the picture data and the speech data which have been recorded at different times are reproduced at the same time.
Further, as a method of using such a rewritable disc, there are instances where plural musical sound data to be reproduced at different times are recorded at the same time. For example, there are instances where plural picture data to be reproduced at different times are recorded at the same time.
Furthermore, as a method of using such a rewritable disc, there are instances where plural picture musical sound data to be reproduced at the same time are recorded at the same time. For example, there are instances where picture data and speech data are respectively recorded at the same time and the picture data and the speech data which have been recorded at the same time are simultaneously reproduced.
In addition, as a method of using such a rewritable disc, there are instances where already recorded plural picture musical sound data are reproduced at the same time while recording plural picture musical sound data.
Also in the case of carrying out recording onto the rewritable disc by using such use methods, when writing is carried out with respect to continuous areas in a manner similar to the case of the tape-shaped recording medium, vast unusable space areas would resultantly take place.
In addition, when picture musical sound data are recorded in a distributed manner as they are with respect to separated usable space areas, one or plural picture musical sound data cannot be continuously outputted simultaneously at the time of reproduction.
An object of this invention is to provide a disc recording method in which in the case where various data continuous in point of time and/or capacity such as picture, speech or musical sound, etc. are recorded onto rewritable disc-shaped recording medium, unusable space areas on such disc-shaped recording medium are reduced so that disc capacity can be efficiently used.
Another object of this invention is to provide a disc recording apparatus in which in the case where various data continuous in point of time and/or capacity such as picture, speech or musical sound, etc. are recorded onto rewritable disc-shaped recording medium, unusable space areas on such disc-shaped recording medium are reduced so that disc capacity can be efficiently used.
A further object of this invention is to provide a disc-shaped recording medium wherein various data continuous in point of time and/or capacity such as picture, speech or musical sound, etc. are recorded in the state where unusable space areas are reduced so that disc capacity can be efficiently used.